It is now a generally accepted view that an improved and accelerated coal utilization program represents one of the important solutions to the national energy crisis problem. However, one of the difficulties of coal utilization is that large amounts of available coal contain relatively large amounts of sulfur which, upon combustion in air, produces the environmentally harmful sulfur dioxide. In addition, the normal combustion process in air, as those in furnaces, produces sufficiently high temperatures to promote the formation of the environmentally harmful oxides of nitrogen. Furthermore, in such processes, carbon monoxide, carbon particulates, as well as fly ash, are generated in the flue gas due to essentially incomplete combustion.
These difficulties are now well recognized, and several solutions have been proposed and implemented, or are in the developmental stage. These include electrostatic precipitators, high energy scrubbers, and fluidized beds. These solutions are all very expensive, and are generally limited to large, central power generation stations.
While the wet-oxidation phenomenon has heretofore been developed into processes applicable to the disposal of solid and chemical wastes, so far as is known such has never been employed as the basis or principal for a coal combustion process. A wet oxidation coal combustion process, it is believed, would be particularly useful for coal with high sulfur content beause in the combustion process the sulfur component is converted into sulfur containing salts which are retained in the process water and thus are not discharged into the environment.